Plant for processing products including a unit for detecting defective products

ABSTRACT

A processing plant, in particular for making respective products, in particular defined by articles or packages of respective articles, the articles being preferably in the form of articles of the tissue industry, the plant including at least one unit for detecting products, in particular defective products, especially defective articles and/or packages, preferably for detecting defective rolls and/or packs.

This application is the National Phase of International ApplicationPCT/162016/051029 filed Feb. 25, 2016 which designated the U.S. and thatInternational Application was published under PCT Article 21(2) inEnglish.

This application claims priority to Italian Application No.6020150000016 filed Feb. 27, 2015, Italian Application No. 6020150000039filed May 4, 2015 and Italian Application No. 202015000025907 filed Jun.19, 2015, which applications are incorporated by reference herein.

TECHNICAL FIELD

This invention relates to a processing plant and, in particular, a plantfor making respective products.

Preferably, the plant produces articles and/or packaging for respectivearticles, in particular in the form of articles of the tissue industry,especially articles made of paper material.

Preferably, the articles are in the form of rolls, tissue handkerchiefs,hand and face wipes, napkins or other, and the packaging is in the formof respective packets, packs, boxes, bags, pallets or other.

BACKGROUND ART

Known in the prior art in the tissue paper industry are plants for theproduction of articles and corresponding packaging, such as rolls andhand or face wipes of paper material, which are packed in correspondingpackets, packs, bags, pallets or other.

Generally speaking, these prior art plants comprise at least oneoperating line including at least one upstream section for making thearticles, in particular in the form of log saws for cutting rolls offrespective elongate logs, and at least one respective packaging section,in particular for primary packaging, preferably in the form of a packingsection where the articles or rolls are packed.

Prior art plants may also include one or more further packagingsections, in the form of a section for cartoning or bagging the packsand/or a section for palletizing the packs or cartons/bags.

Prior art plants also include conveying means by which the products aretransported between one section of the plant and another, in particularbetween the means which make the articles and the respective packagingsection and between one packaging section and another in the downstreampart of the plant.

However, in plants of the above mentioned type in the tissueindustry—but also in plants for making other types of products—,although the large quantities of articles made are of satisfactoryquality, a certain number of defective end products are produced whichare only occasionally removed, completely manually, by machine operatorsand which, unfortunately, are placed on the market and eventually reachend users.

Even today, therefore, prior art plants of this kind continue to producedefective products which do not measure up to consumer qualitystandards.

Moreover, in prior art plants of this kind, it is difficult to promptlydetermine the causes of defective products with any degree of certainty.

In short, prior art plants of this kind produce non-negligiblequantities of defective products which machine operators find itdifficult to pick out but which nevertheless lead to production lossesfor the companies which use these production plants.

Furthermore, there is also in the industry a generally felt need formachinery and equipment which are relatively low in cost and/or which donot have excessive impact on normal production activities.

Yet another need felt by the industry is that for machinery andequipment that is easy for operators to install and/or use.

DISCLOSURE OF THE INVENTION

This invention therefore proposes a new solution as an alternative tothe solutions known up to now and, more specifically, proposes toovercome one or more of the above mentioned drawbacks and/or problemsand/or to meet one or more of the needs felt in the trade or inferablefrom the above.

Accordingly, it is provided a processing plant, in particular for makingrespective articles or packages of respective articles; the articlesbeing preferably in the form of articles of the tissue industry, such asrolls, handkerchiefs, hand and face wipes, napkins or other productsmade of paper material, and the packaging being preferably in the formof packets, packs, boxes, bags, pallets or other; preferably the plantcomprises at least one operating line including at least one upstreamsection for making the articles, in particular in the form of a log sawfor cutting rolls off respective elongate logs, at least one respectivepackaging section, in particular for primary packaging, preferably inthe form of a packing section where the articles or rolls are packed andpreferably at least one or more further packaging sections, inparticular in the form of at least one bagging section where the packsare placed in bags and/or one palletizing section where the packs orbags are placed on pallets; the plant further comprising a conveyingsection, or means, by which the products are transported between onesection of the plant and another, in particular between the means whichmake the articles and the respective packaging section and/or betweenone packaging section and another downstream; characterized in that itcomprises at least one unit for detecting products, in particulardefective products, especially articles and/or packages, and preferablyin the form of a unit for detecting rolls and/or packs, in particulardefective rolls and/or packs.

That way, it is possible to ascertain the actual number of defectiveproducts made in the corresponding plant and, in particular, in a plantof the tissue industry.

BRIEF DESCRIPTION OF THE DRAWINGS

This and other innovative aspects are set out in the appended claims andits technical features and advantages are apparent from the detaileddescription which follows of a preferred, advantageous embodiment whichmust, however, be considered purely as a non-limiting example of theinvention; the description being made with reference to the accompanyingdrawings, in which:

FIG. 1 shows a schematic plan view of a preferred embodiment of theplant of the tissue industry according to this invention, adapted to usea preferred embodiment of a unit for detecting products, in particulardefective products;

FIG. 2 shows a perspective view of a first preferred embodiment of aunit according to the invention for detecting products, in particulardefective products, located along the respective product conveying line;

FIG. 3 shows a screenshot of the products being processed;

FIG. 4 shows a screenshot of the products being processed, alternativeto the screenshot shown in FIG. 3;

FIGS. 5A to 5H show different configurations of defective products asdetected and displayed by the unit;

FIG. 6 is a schematic perspective view of a second preferred embodimentof the product detection unit;

FIG. 7 is a side view of the second preferred embodiment of the unitaccording to the invention;

FIG. 8 is a schematic top plan view of the second preferred embodimentof the unit according to this invention;

FIG. 9 shows a perspective view of a type of pack which can be processedby this plant.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

FIG. 1 illustrates a preferred embodiment 10 of a processing plant, inparticular for making respective products, where respective articlespacked in respective packages are made.

Preferably, the articles are in the form of articles of the tissueindustry, such as rolls, handkerchiefs, hand and face wipes, napkins orthe like, made of paper material.

More specifically, the rolls are in the form of rolls of toilet paperand/or kitchen paper.

The packages are in turn preferably in the form of packets, packs,boxes, bags, pallets or other.

More specifically, the plant 10 comprises at least one operating linewhich includes at least one upstream section 1, for making the articles,in particular in the form of rolls, the upstream section being, inparticular in the form of a log saw machine for cutting the rolls from arespective elongate log. As illustrated, the log saw machine comprisesmeans 1′ for making the log and means 1″ for cutting the rolls from thelog.

The plant 10 also comprises at least one packaging section 2, inparticular for primary packaging, preferably in the form of a sectionfor packing the articles or rolls, in particular in a respective film,preferably a plastic wrapping film.

More specifically, as illustrated, the example embodiment describedherein comprises a first and a second primary packaging section 2, 2,fed by respective conveying sections, or lines, 5.

Downstream of the respective primary packaging section 2, the plant alsocomprises at least one or more further packaging sections 3 and/or 4.

More specifically, as illustrated, there are means or sections forbagging the packs, namely, a first and a second bagging section 3downstream of the respective packing machines 2, and an end palletizingsection 4 which receives the products through corresponding conveyinglines from the respective bagging machine or directly from therespective packing machine 2.

As illustrated, the plant comprises a respective conveying section, ormeans 5, by which the products are transported between one section ofthe plant and another, in particular between the means 1 which make thearticles and the respective packaging section 2 and/or between onepackaging section and another downstream.

More specifically, as illustrated, the conveying means 5 comprise means512 for conveying the products between the section which makes thearticles 1 and the respective packing section 2 and which comprise arespective stage, or apparatus, 5′ for directing the flows of articlesfeeding out of the machine which makes the articles 1 towardscorresponding lines leading to the respective packing machines 2, 2.

Also, as illustrated, the conveying means 5 comprise respectiveconveying means 523 running between the corresponding packing section 2and the respective bagging section 3, as well as conveying means 534running between the respective bagging section and the palletizingsection 4.

As illustrated, the use of conveying means 524 running between therespective packing section 2 and the palletizing section 4 is alsocontemplated.

As illustrated, the conveying means comprise a plurality of parallelconveying lines or belts for corresponding pluralities of articlesand/or packages. More specifically, as illustrated, four parallelconveyor belt lines are used in the stretches 512 of the conveyingmeans.

Advantageously, the plant comprises at least one unit 12, illustrated inFIG. 2, for detecting products, in particular defective products,especially articles and/or packages, and preferably in the form of aunit for detecting rolls and/or packs, in particular defective rollsand/or packs.

By way of example, the unit of the invention is adapted to work withrolls of different sizes, for example rolls whose diameter is preferablybetween 90 mm and 200 and whose length is preferably between 90 mm and280 mm.

The unit of the invention is also adapted to work with rolls made ofwhite or coloured paper or paper printed with respective logos, images,designs or decorations.

More specifically, the unit 12 for detecting products, in particulardefective products, is advantageously situated at the conveying means ofthe plant, in particular at the conveying section 512 located betweenthe section 1 which makes the articles, in particular the log saw whichcuts off the rolls, and the respective packaging section 2, inparticular defined by the corresponding packing machine.

Preferably, the unit of the invention is located at the outfeed of thelog saw, or section for making the articles 1.

More specifically, the unit 12 for detecting products, in particulardefective products, might also be located at the respective conveyingsection 523, 524, downstream of the respective packaging section 2,and/or at the respective conveying section 534, downstream of therespective bagging section 3.

Advantageously, the unit 12 for detecting products, in particulardefective products, comprises means 14, 16, 18 for capturing at leastone corresponding image, in particular a plurality of images, of therespective product.

More specifically, the unit 12 for detecting products, in particulardefective products, thus advantageously comprises image capturing meansembodied by camera means 14, 16, 18 adapted to capture one or moreimages of the respective product, even in the form of correspondingsequences of images.

More specifically, the camera means are in the form of one or morecameras known as “smart cameras”, which comprise respectivemicroprocessor means which allow controlling image capturing and whichprimarily process the captured images as a function of specificoperating needs which will become clearer as this description continues.

Advantageously, therefore, the mode of detecting the product by thecamera means 14, 16, 18 can be modified according to specific productimage capturing requirements.

Advantageously, therefore, capturing means 14 are provided which areadapted to take snapshots of the product from above in order to obtainor capture at least one image of the top face or surface 11 a of therespective product or roll.

It is thus possible to detect corresponding characteristics of theproduct.

More specifically, capturing images of the product from above allowsinspecting the length, width and/or exterior aspect of the correspondingoutside surface of the respective product, that is, also the conditionor state of the respective end flap of the roll as will become cleareras this description continues.

Also advantageously provided are capturing means 16 which can takesnapshots of the product from the front in order to capture at least onecorresponding image of the front face 11 b of the respective product orroll.

It is thus possible to detect corresponding characteristics of theproduct, in particular those which can be inferred from its front face.

Also advantageously provided are capturing means 18 which can takesnapshots of the product from the back in order to capture at least onecorresponding image of the rear face 11 c of the respective product orroll.

It is thus possible to detect corresponding characteristics of theproduct, in particular those which can be inferred from its rear face.

More specifically, as illustrated in FIG. 2, the unit 12 advantageouslycomprises respective camera means which include a camera 14 locatedabove the means 5 for conveying the product 11 to be detected.

More specifically, the camera 14 has a respective lens 14′ which isdirected, that is, whose optical axis is directed, perpendicularly orsubstantially perpendicularly, to the product supporting andtransporting surface 15′ of the corresponding conveying means 5.

That way, it is particularly easy to take snapshots of the top face ofthe product, in particular without interfering with the productconveyor, that is to say, without substantially disturbing normal plantoperation.

Advantageously, as illustrated, the camera means comprise acorresponding camera and, in particular, a first and a second camera 16,18, which are respectively located above the product conveying meansand, in particular, whose respective lens, or the respective axisthereof, or the respective optical axis thereof, is inclined at arespective angle to the product supporting surface 15′ of the conveyingmeans 5.

That way, it is easy to take snapshots of the front and/or rear face ofthe product, in particular without interfering with the productconveyor, that is to say, without substantially disturbing normal plantoperation.

More in detail, the camera means advantageously comprise a correspondingcamera 16 whose respective lens 16′ is inclined at a respective angle tothe product supporting surface 15′ of the conveying means 5, the lens16′ being directed in the direction opposite to the product feeddirection.

That way, it is easy to take snapshots of the respective front face ofthe product without substantially disturbing normal plant operation.

Further, as illustrated, the camera means comprise a correspondingcamera 18 whose respective lens 18′ is inclined at a respective angle tothe product supporting surface 15′ of the conveying means 5, the lens18′ being directed in the same direction as the product feed direction.

That way, it is easy to take snapshots of the respective rear face ofthe product without substantially disturbing normal plant operation.

More specifically, as may be inferred from the drawings, the camerameans comprise a corresponding camera 14, 16, 18, whose respective lens14′, 16′, 18′ is positioned at the transverse centre line of the productsupporting surface 15′ of the conveying means 5, and in particular, atthe transverse centre line of the product 11 to be detected.

More specifically, the camera means 14, 16, 18 are advantageouslypositioned above the conveying means 5 at a distance from the productsupporting surface 15′ of the selfsame conveying means 5 such that theyare higher up than the maximum height of the corresponding product to bedetected as it moves along the conveying means 5, or such as to behigher up than the maximum height reachable by a plurality of producttypes or sizes which can be processed in the plant of the invention.

That means it is advantageously possible to avoid having to adjust theposition of the camera means during changeovers.

More specifically, the camera means 14, 16, 18 advantageously have arespective depth of field, that is, a depth or length where therespective image is “in focus”, that is to say, a clear image, and whichis suitable for detecting a plurality of products of different sizes, inparticular different heights and diameters, as they move forward alongthe conveying means 5. For example, the respective depth of field of thecamera means 14, 16, 18 is suitable for taking snapshots of, or keepingin focus, rolls between 90 mm and 200 mm in diameter without carryingout any adjustments.

That way, it is not necessary to adjust the focus of the respectivecamera means when changing over to products of a different size.

Advantageously, the unit 12 for detecting products, in particulardefective products, operates while the products 11 move along therespective conveying means 5, that is to say, while the products aremoving forward or performing the respective feed movement.

In practice, the detection means—or camera means—14, 16, 18 operatewhile the products 11 advance on the respective conveying means 5, thatis to say, they capture images of the products while the products are inmotion.

More specifically, the unit 12 for detecting products, in particulardefective products, operates with products moving forward at a speed ofbetween 235 and 400 rolls per minute.

That way, any defective products can be detected without substantiallydisturbing normal plant operation and without causing production lossesin the plant where the unit is installed.

More specifically, the perpendicular camera 14 is preferably a colourcamera, whilst the inclined cameras 16 and 18 are preferably black andwhite cameras.

It will be understood, however, that the cameras and correspondingilluminators, which are described in more detail below, may be sensitiveto electromagnetic radiation in one or more of the infrared, visible orultraviolet fields.

Advantageously, also, the unit 12 for detecting products, in particulardefective products, comprises respective means 20, 20, 22, 24 forlighting the product at the respective detection zone.

That way the product to be detected can be viewed specifically andoptimally.

More specifically, the lighting means advantageously comprise acorresponding illuminator, in particular a first and a secondilluminator, or lamp, 20, 20, at the respective camera 14 whose lens 14′is directed perpendicularly or substantially perpendicularly to theproduct supporting surface 15′ of the conveying means 5.

That way, the top face of the product to be detected is viewed inoptimum manner.

More specifically, the lighting means advantageously comprise a firstand a second illuminator, or lamp, 20, 20, which are positioned alongthe longitudinal feed direction of the products upstream and downstreamof the respective camera 14 whose lens 14′ is directed perpendicularlyor substantially perpendicularly to the product supporting surface 15′of the conveying means 5.

Advantageously, the lighting means comprise a corresponding illuminatoror lamp, 22, 24, at the respective camera 16, 18 whose lens 16′, 18′ isinclined to the product supporting surface 15′ of the conveying means 5.

That way, the respective transverse, front or rear face of the productto be detected is viewed in optimum manner.

More specifically, as illustrated, the lighting means comprise acorresponding illuminator or lamp, 22, 24, which is advantageouslydirected towards the respective camera 16, 18 whose lens 16′, 18′ isinclined to the product supporting surface 15′ of the conveying means 5.

Advantageously, as illustrated, the lighting means comprise acorresponding illuminator or lamp, 22, 24, which is positioned along thelongitudinal feed direction of the products upstream and downstream ofthe respective camera at the respective camera 16, 18 whose lens 16′,18′ is inclined to the product supporting surface 15′ of the conveyingmeans 5.

As illustrated, the lighting means advantageously comprise at least onecorresponding illuminator, or lamp, in particular a first and a secondilluminator 22, 24, the respective illuminator being positioned alongthe longitudinal feed direction of the products between the respectivecameras 16 and 18 whose respective lenses 16′, 18′ are inclined to theproduct supporting surface 15′ of the conveying means 5.

Advantageously, the lighting means comprise a corresponding illuminatoror lamp, 22, 24, which is located at substantially the same height asthe respective camera 16, 18 whose lens 16′, 18′ is inclined to theproduct supporting surface 15′ of the conveying means 5.

Advantageously, the lighting means then comprise a correspondingelongate illuminator, or elongate lamp, 20, 20, 22, 24 which extendstransversely to the longitudinal direction of product feed andpositioned centrally relative to the centre line of the conveying means5, or rather, of the product supporting surface 15′ of the conveyingmeans 5.

Particularly advantageously, the lighting means 20, 20, 22, 24 arecontrolled in such a way as to view or illuminate the product variably,in particular as a function of the specific image to be captured,preferably as a function of the detail of the product to be specificallydetected and inspected.

That way, the product is viewed in the optimum manner, in particularallowing its specific, potentially faulty characteristic to be detected.

Also imaginable is the use of distinct illuminators to light differentparts of the product to allow taking images or sequences of images ofcorresponding details of the product.

Advantageously, the unit 12 for detecting products, in particulardefective products, comprises means 28, 30, 32 for reflecting theradiation used to light the product, in particular the radiation emittedby the illuminator means 20, 20, 22, 24.

That way, the product to be detected, or rather, the specific zone ofthe product to be detected, can be viewed in the optimum manner.

More specifically, the means for reflecting the radiation used to lightthe product advantageously comprise a respective reflecting screen 28 atthe camera 14 whose lens 14′ is directed perpendicularly orsubstantially perpendicularly to the product supporting surface 15′ ofthe conveying means 5, the reflecting screen 28 being, in particular,located downstream of the camera 14 along the longitudinal direction ofproduct feed.

As illustrated, the means for reflecting the radiation used to light theproduct advantageously also comprise a reflecting screen, in particularfirst and second reflecting screens 30, 32, located, respectively, atthe cameras 16, 18 whose lenses 16′, 18′ are inclined to the productsupporting surface 15′ of the conveying means 5.

In particular, as illustrated, the respective screen 30 or 32 islocated, respectively, upstream or downstream, of the respective camera16 or 18 along the longitudinal direction of product feed.

More specifically, as illustrated, the respective reflecting screen 30or 32 is provided on the longitudinal side of the respective camera 16or 18 opposite the side where the corresponding lighting means 22, 24are located, being situated, in particular, just behind the respectivecamera means 16, 18.

Advantageously, the unit 12 for detecting products, in particulardefective products, comprises means 34, 36, 38 for activating productdetection by corresponding camera means 14, 16, 18.

That way, product detection by the camera means can be activatedconveniently and promptly.

Advantageously, the unit 12 for detecting products, in particulardefective products, comprises means 34, 36, 38 for activating detectionof the respective product by the means 14, 16, 18 for capturing at leastone corresponding image of the respective product, in particular by thecorresponding camera means 14, 16, 18.

That way, product detection is advantageously activated at exactly theright time and only when strictly necessary.

More specifically, the means for activating product detection comprisesensor means for detecting the presence of the product at the respectivedetection zone and being, in particular, in the form of photocell means34, 36, 38.

More specifically, advantageously, the means 34, 36, 38 for activatingproduct detection emit a corresponding signal for activating detectionwhen the product reaches a defined detection zone or when the productleaves a defined detection zone, that is to say, when it covers oruncovers a respective photocell located at the respective detectionzone.

More specifically, the means 34, 36, 38 for activating detection arelocated at the conveying means 5.

More specifically, means 34 are provided for activating detection by thecamera 14 whose lens 14′ is directed perpendicularly or substantiallyperpendicularly to the product supporting surface 15′ of the conveyingmeans 5 and which are situated at the camera 14 itself and emit acorresponding activation signal when a product reaches the activationmeans 34 themselves, in particular, when the product is substantiallycentred longitudinally relative to the camera means 14.

Also provided are means 36 for activating detection by the respectivecamera 16 whose lens 16′ is inclined to the product supporting surface15′ of the conveying means 5, these activating means 36 being situatedupstream of the camera 16 itself at the zone of detecting thecorresponding transverse face of the product and emitting acorresponding signal for activating the camera 16 when the productreaches the activation means 36 themselves.

Also provided are means 38 for activating detection by the respectivecamera 18 whose lens 18′ is inclined to the product supporting surface15′ of the conveying means 5, these activating means 38 being situateddownstream of the camera 18 itself at the zone of detecting thecorresponding transverse face of the product and emitting acorresponding signal for activating the camera 18 when the productuncovers, or moves away from, the activation means 38 themselves.

Advantageously, at the unit 12 for detecting products, in particulardefective products, in particular at the means 14, 16, 18 for capturingat least one corresponding image of the respective product, the productsare spaced apart along their longitudinal feed direction preferably by aspacing such as to allow capturing a corresponding transverse image,preferably complete, of the respective front and/or rear face of theproduct.

Advantageously, although not specifically illustrated in theaccompanying drawings, the plant of the invention may comprise, upstreamof the product detection unit 12, corresponding means for spacing theproducts being conveyed.

That way, it is possible to detect the product in optimum manner, and inparticular to detect the front and rear transverse surfaces of theproduct.

More specifically, the longitudinal spacing between the products is afunction of the dimensions or size of the respective product or roll.

For example, for rolls 110 mm in diameter, the spacing between twoconsecutive rolls may be between 75 mm and 85 mm.

Advantageously, the unit 12 for detecting products, in particulardefective products, comprises electronic processing means 40, inparticular in the form of an industrial PC provided with correspondingprogram means or software means.

More specifically, advantageously, the electronic processing means 40receive data corresponding to at least one image of the respectiveproduct from the means for capturing at least one corresponding image ofthe product, in particular from the camera means 14, 16, 18.

The electronic processing means 40 then process the image and determinewhether the product has any defect or defects.

Advantageously, the electronic processing means 40 process the image anddetermine at least one corresponding parameter representing a particularproduct characteristic to be assessed.

The electronic processing means 40 then determine whether the product isdefective or acceptable by assessing whether the parameter representinga particular characteristic of the product falls outside or inside adefined tolerance range around a predetermined reference value.

The predetermined reference value is determined by processing at leastone image of at least one corresponding product whose respectivecharacteristic is optimal or, in any case, compliant withspecifications.

Advantageously, the tolerance value around the respective referencevalue can be selected or set at will, in particular by the operator incharge, for example using an input keyboard forming part of theelectronic processing means 40.

For different product characteristics, the electronic processing means40 might also determine the level of product defectiveness oracceptability on a predetermined scale of values of the parameterrepresenting a particular characteristic of the product.

The level on the predetermined reference scale is differentiated orclassified based on a corresponding predetermined threshold value.

More specifically, the reference scale might have three differentlevels, respectively defining a product which is without defects, orsubstantially without defects, a product which is defective butacceptable and a product which is defective and unacceptable. Theremight also be a fourth reference level to indicate a severely defectiveproduct.

The electronic processing means 40 are also adapted to determine whetherthe product must be considered defective and non-conforming, orconformant and acceptable by combining together the parameters or scoresobtained from the detection of different product defects.

In practice, the parameters or scores obtained from the detection ofdifferent product defects are suitably weighted and combined to give atotal value or score.

In a preferred embodiment, the total defect score or value isconveniently compared with a predetermined reference value in order todetermine whether the product is non-conforming and, for example, mustbe rejected, or is conformant and, for example, must not be rejected.

More specifically, the “weighting”, that is, the value by which theparameter or score of the respective defect is weighted might begreater, i.e. higher, for defects considered particularly serious, suchas, for example, dirt on the transverse surface resulting from cuttingthe roll, or smaller, i.e. lower, for defects considered less serioussuch as, for example, embossing which is not centred on the outsidesurface of the roll.

Advantageously, as may be inferred from FIGS. 2 and 3, the electronicprocessing means 40 trigger an operator alert procedure if theydetermine that the respective product is non-conforming.

More specifically, the alert procedure entails issuing a signal,preferably a light signal by means of an alarm lamp 42 at the detectionunit 12, and/or a corresponding sound signal.

Advantageously, the electronic processing means 40 also send acorresponding message, in particular, an alarm or detected defectmessage, to the telephone, in particular, the mobile phone 44, or toanother terminal device, in the operator's possession. Morespecifically, such a message might be sent to the operator only onreaching a predetermined, convenient defectiveness threshold or level,which might be selectively settable, if necessary.

The electronic processing means 40 also trigger a corresponding operatoralert procedure through corresponding display means, in particularthrough the display means 46 of the unit 12 for detecting the products,in particular the defective products.

As may be inferred in particular from FIG. 3, the electronic processingmeans 40 advantageously cause to be displayed on the respective displaymeans, in particular on the display means 46 of the unit 12 fordetecting the products, in particular the defective products, agraphical interface or screen 48, which comprises at least one field 54,56, 58 showing the respective product image captured by the imagecapturing means, and more specifically, by the camera means 14, 16,18.

In practice, advantageously, as shown in FIG. 3, the electronicprocessing means 40 display on the respective display means, inparticular on the display means 46 of the unit 12 for detecting theproducts, in particular the defective products, a respective graphicalinterface or screen 48, which comprises a field 54 showing a respectiveimage of the product or roll captured by the camera 14 whose lens 14′ isdirected perpendicularly or substantially perpendicularly.

Also, advantageously, as shown in FIG. 3, the electronic processingmeans 40 display on the respective display means, in particular on thedisplay means 46 of the unit 12 for detecting the products, inparticular the defective products, a respective graphical interface orscreen 48, which comprises a field 56 showing a respective image of theproduct or roll captured by the camera 16 whose lens 16′ is inclined andwhich captures an image of the front face of the product, and a field 58showing a respective image of the product or roll captured by the camera18 whose lens 18′ is inclined and which captures an image of the rearface of the same product.

Further advantageously, the electronic processing means 40 display onthe respective display means, in particular on the display means 46 ofthe unit 12 for detecting the products, in particular the defectiveproducts, a respective graphical interface or screen 48, which comprisesan information field 51 which indicates whether the product is defectiveor conformant.

Further advantageously, the electronic processing means 40 display onthe respective display means, in particular on the display means 46 ofthe unit 12 for detecting the products, in particular the defectiveproducts, a respective graphical interface or screen 48, which comprisesone or more information fields 53 which indicate whether a specificcharacteristic of the product is defective or conformant.

As illustrated, the respective information field 51, 53 mayadvantageously be of the traffic light type, or of the varying colourtype, from green to red, when the product or the specific characteristicthereof is conformant or non-conforming, i.e. defective.

Also, as illustrated, the electronic processing means 40 advantageouslydisplay at the respective information field 51, 53 a text 55, orpossibly a drawing 55′ (as shown in FIG. 4), which indicates orhighlights the specific aspect or defect or product characteristic therespective information field 51, 53 refers to.

More in detail, the electronic processing means 40 advantageouslydetermine the length and/or the width of the respective product or roll,determining it in particular through an image transmitted by the camera14 whose lens 14′ is directed perpendicularly or substantiallyperpendicularly, and thus determine whether the length and/or width isnon-conforming, i.e. defective, or conformant, i.e. exact.

More specifically, the processing means 40 determine whether the lengthand/or the width of the respective product or roll falls within acertain tolerance interval, in particular a respective preset value forthe specific size of product or roll detected. An example of a rollwhose length is non-conforming, as detected by the present defectdetection unit 12 and displayed on the respective display means 46, isshown in FIG. 5C.

Advantageously, the electronic processing means 40 determine the stateof the outside surface of the product or roll, determining in particularthe value of a corresponding parameter, and more specifically,determining it through an image transmitted by the camera 14 whose lens14′ is directed perpendicularly or substantially perpendicularly, andthus determine whether the outside surface is non-conforming, i.e.defective, or conformant. An example of a roll whose outside surface isnon-conforming, as detected by the present defect detection unit 12 anddisplayed on the respective display means 46, is shown in FIG. 5F.

Advantageously, the electronic processing means 40 determine theposition of the product or roll, determining in particular the value ofa corresponding parameter, and more specifically, determining it throughan image transmitted by the camera 14 whose lens 14′ is directedperpendicularly or substantially perpendicularly, and thus determinewhether the position is defective, i.e. incorrect, or conformant, i.e.correct. More specifically, a roll in an incorrect position might be aroll whose axis is rotated by 90° and whose respective transverse faceis resting on the supporting surface 15′ of the conveyor 5. An exampleof a roll whose position is non-conforming or incorrect, as detected bythe present defect detection unit 12 and displayed on the respectivedisplay means 46, is shown in FIG. 5E.

Advantageously, the electronic processing means 40 determine whether thecore of the product or roll is misshapen, determining in particular thevalue of a corresponding parameter, and more specifically, determiningit through an image transmitted by the camera 16, 18 whose lens 16′, 18′is inclined, and thus determine whether the core is non-conforming, i.e.defective, or conformant. More specifically, the level on apredetermined graduated scale the respective parameter falls into isdetermined, the predetermined graduated scale being specific to therespective size of product or roll detected. An example of a roll havinga misshapen, non-conforming core, as detected by the present defectdetection unit 12 and as displayed on the respective display means 46,is shown in FIG. 5B.

Advantageously, the electronic processing means 40 determine whether therespective transverse face of the product or roll is dirty, determiningin particular the value of a corresponding parameter, and morespecifically, determining it through an image transmitted by the camera16, 18 whose lens 16′, 18′ is inclined, and thus determine whether thetransverse face is defective, i.e. dirty, or conformant, i.e. clean orslightly dirty. More specifically, the level on a predeterminedgraduated scale the respective parameter falls into is determined. Anexample of a roll having a dirty, non-conforming transverse face, asdetected by the present defect detection unit 12 and as displayed on therespective display means 46, is shown in FIG. 5G.

Advantageously, the electronic processing means 40 determine whether thelogo or the printed text, design or decoration on the outside surface ofthe product or roll is correctly positioned or centred, determining inparticular the value of a corresponding parameter, and morespecifically, determining it through an image transmitted by therespective camera 16, 18 whose lens 16′, 18′ is inclined, and thusdetermine whether the centring is non-conforming, i.e. defective, orconformant. More specifically, the processing means determine whetherthe centring of the logo falls within a certain tolerance interval. Anexample of a roll where the logo on the outside surface of the productor roll is not correctly positioned or centred, as detected by thepresent defect detection unit 12 and as displayed on the respectivedisplay means 46, is shown in FIG. 5D.

Also, advantageously, the electronic processing means 40 determinewhether the printing and embossing on the outside surface of the productare centred.

Advantageously, the electronic processing means 40 also determinewhether the winding or rewinding of the product or roll is irregular.

Advantageously, the electronic processing means 40 also determinewhether the core of the product or roll is missing.

Advantageously, the electronic processing means 40 also determinewhether the end flap of the product or roll is detached or excessivelylong. An example of a roll having a non-conforming end flap, as detectedby the present defect detection unit 12 and as displayed on therespective display means 46, is shown in FIG. 5H.

An example of a perfectly conformant roll, as detected by the presentdefect detection unit 12 and as displayed on the respective displaymeans 46, is shown in particular in FIG. 5A.

Advantageously, the electronic processing means 40 also determinewhether the transverse end face of the product or roll after being cutoff is oblique.

Advantageously, the electronic processing means 40 provide defecttracking means used, in particular, for statistical purposes.

More specifically, the tracking means are advantageously adapted tocount the number of rolls inspected and provide a total figure ofproduction defectiveness, as well as the percentage of each singledefect.

More specifically, the tracking means are, advantageously, adapted toindicate the type of rolls, the specific production session and theproduction batch. This data is conveniently stored with, or correlatedto, the defects identified.

More specifically, the tracking means advantageously store the images ofthe defective products and associate them with the respective productiondata.

Advantageously, the images of non-defective products can also be takenand sampled, for example for purposes of statistical comparison with thedefective products.

To do this, the defect tracking means might also be in the form of filefolders, each containing image files of products having a respectivedefect, accompanied by images of non-defective products and/or arespective table or the like showing, for each defective productdetected, the date, time and type of defect detected.

Advantageously, the predetermined reference or threshold values of thegraduated scale differ according to the type and/or size of the productto be checked.

Advantageously, the predetermined reference or threshold values of thegraduated scale are stored in a respective memory, in particular of theelectronic processing means 40 of the unit 12 for detecting products, inparticular defective products, and can preferably be called up manuallyby the operator or set automatically when the corresponding product typeand/or size is processed.

Advantageously, also, the electronic processing means 40 are connected,at 47, to the plant control and/or management means.

Advantageously, the plant of the invention includes means foreliminating the defects detected and which might be in the form of meanswhich directly correct, or simply indicate, the cause, upstream, whichled to the production of a defective product.

More specifically, the means for eliminating the defects are in the formof means which, after the defects have been detected, send acorresponding signal to the control means of the device of the processmachine, or operating section, situated upstream, so that the process inwhich the defect is produced can be corrected.

Further, the means for eliminating the defects might also be in the formof means for expelling the non-conforming products.

More specifically, the invention might contemplate the provision of alateral expulsion unit, not illustrated in detail in the accompanyingdrawings and, for example electro-pneumatically driven, to expelnon-conforming rolls, in conjunction with conveyor belt means andprovided with respective control systems.

FIGS. 6 to 8 illustrate a second preferred embodiment 120 of the unitfor detecting the products, in particular defective products and whichis particularly suitable for detecting corresponding packs of articles,in particular packs of rolls 112.

FIG. 9 shows a preferred or typical embodiment 50 of a pack of rolls 11which can be processed in the plant of the invention and illustrated, inparticular, under normal conveying conditions.

As illustrated, the pack 50 comprises a plurality of rolls 11, suitablypositioned and held together by a respective outer wrapper 51,preferably made of plastic material, sealed on its lateral faces 52, 53and underside face 54. Only the seal on the face 53 is shown in FIG. 9.Further, the top face 55 of the pack is normally provided with atrademark or logo and/or other graphical elements. Further graphicalelements, for example a barcode, may be provided on the underside face54 of the product or pack.

The second preferred embodiment 120 comprises means 14 for detectionfrom above which are similar in every way to those of the firstpreferred embodiment described above and which are not commented onagain so as to avoid making this description too lengthy.

The second preferred embodiment 120 of the unit for detecting products,in particular defective products, advantageously comprises imagecapturing means 150 which are adapted to take snapshots of the productfrom below in order to capture at least one image of the underside face112 i of the respective product.

It is thus possible to detect corresponding features present on theunderside face of the product.

Further advantageously, the second preferred embodiment 120 of the unitfor detecting products, in particular defective products, comprisesimage capturing means 170, 190 which are adapted to take snapshots ofthe product from a respective side in order to capture at least oneimage of the corresponding lateral face 112 s, 112 d of the respectiveproduct.

More specifically, as illustrated, the image capturing means 170, 190are adapted to take snapshots of the product from both sides in order tocapture at least one image of the corresponding lateral face 112 s, 112d of the respective product.

It is thus possible to detect corresponding features present on thecorresponding lateral face of the product.

The second 120 of the unit for detecting products, in particulardefective products, uses a camera 14 positioned above, whose respectivelens 14′ is directed perpendicularly or totally perpendicularly to theproduct supporting surface 15′ of the corresponding conveying means 5and which is similar in every way to the one of the first preferredembodiment.

Advantageously, in the second preferred embodiment 120, the camera meanscomprise a corresponding camera positioned laterally of the productconveying means 15, in particular a first and a second camera 170, 190positioned on opposite sides of the product conveying means 15 and, inparticular, whose respective lens 170′, 190′ is directed parallel orsubstantially parallel to the product supporting surface 15′ of theconveying means 5.

In practice, as illustrated, in the second preferred embodiment, thecamera means advantageously comprise a corresponding camera positionedlaterally of the product conveying means, in particular a first and asecond camera 170, 190 positioned on opposite sides of the productconveying means 15 and, in particular, whose respective lens 170′, 190′is directed at, or substantially at, the perpendicular centre line ofthe product to be detected.

Advantageously in the second preferred embodiment, the camera meanscomprise a corresponding camera 150 which is positioned under theproduct conveying means and, in particular whose respective lens 150′ isdirected perpendicularly or substantially perpendicularly to the productsupporting surface 15′ of the conveying means 5.

That way, it is easy to take snapshots of the underside face of theproduct, in particular without interfering with the product conveyor,that is to say, without substantially disturbing normal plant operation.

More specifically, the camera means advantageously comprise a camera 150which is positioned under the product conveying means and, inparticular, whose lens 150 is positioned at the transverse centre lineof the conveying means 5, in particular at the transverse centre line ofthe product 11 to be detected.

It will be understood, however, that corresponding detection means, inparticular of the camera type, similar to the ones denoted by thereference numeral 150 and which take snapshots of the product from belowmight also be used in the first preferred embodiment describedpreviously.

More specifically, advantageously, the conveying means 5 compriseopening means 15 a for detection of the product by the camera 190positioned below.

More specifically, advantageously, the conveying means 5 comprise, atthe opening means 15 a, corresponding conveying means, or rotating belts150, 150 which engage and feed the product forward as it passes by theopening means 15 a. As illustrated, the product feed means 150, 150simultaneously engage the respective product 112 from opposite sides.

More specifically, as illustrated, the top and bottom detection meansare situated in a zone of the conveying means which is separate from thezone in which the means for detecting the lateral faces of the productare situated, the means 170, 190, for detecting the lateral faces being,as illustrated, preferably situated in a zone upstream of the zone whereboth of the cameras 14, 150 with the perpendicularly directed lenses aresituated.

According to the second preferred embodiment of the unit for detectingproducts, in particular defective products, the corresponding electronicprocessing means advantageously determine, or are adapted to determine,whether the printing on the wrapper of the product or pack is notcentred or well positioned.

In the second, preferred embodiment, the respective electronicprocessing means also advantageously determine, or are adapted todetermine, whether the product or pack, or rather, the related wrapper,is incorrectly sealed.

In the second, preferred embodiment, the respective electronicprocessing means also advantageously determine, or are adapted todetermine, whether the product or pack, or rather, the related wrapper,contains an article that is incorrectly positioned or rotated.

In the second, preferred embodiment, the respective electronicprocessing means also advantageously determine, or are adapted todetermine, whether there is paper trapped in the seal of the product orpack, or rather, of the related wrapper.

In the second, preferred embodiment, the respective electronicprocessing means also advantageously determine, or are adapted todetermine, whether there is a break in the wrapping film (for example, ahole caused by excessive heat during sealing or by tearing).

The unit of the second preferred embodiment in turn comprises respectivelighting means, suitably controlled and connected to respectivedetection or camera means, not illustrated in detail in the accompanyingdrawings and which may be similar in every way to those describedpreviously in connection with the first preferred embodiment.

Advantageously, the plant of the invention includes means foreliminating the defects detected, in particular in the form of meanswhich remove the defective product, such as the ones denoted by thereference numeral 121 in FIG. 3, which eliminate the defective packsfrom the conveying line, in particular by means of corresponding meansfor engaging and pushing the product 112 off the conveying line 5.

Although not illustrated in detail in the accompanying drawings, thedefect detection unit 12, 120 is, with the exception of the processingand defective product display means, housed in an enclosure, preferablyof an openable type, which hides the detection zone from the externalenvironment and which is open at its opposite ends, or which comprisesopen transverse end walls, to allow the product to exit the detectionunit 12 itself.

Moreover, the cameras of the invention may be equipped with filters tohighlight the wavelengths most suitable for the detection to be carriedout, in particular as a function of the wavelength of the light sourcesor emitters used.

The invention described above is susceptible of industrial application.It would be obvious to one skilled in the art that several changes andmodifications can be made to the invention without departing from thespirit and scope of the invention, described in depth above. It is alsoeasy to imagine further embodiments of the invention comprising one ormore of the features described herein. Moreover, it will be understoodthat all the details of the invention may be substituted for technicallyequivalent elements.

The invention claimed is:
 1. A processing plant for making paper rollproducts, comprising: a conveying section including a conveyor with aproduct supporting surface by which paper roll products are transportedbetween one section and another; an electronic process control forcontrolling functioning of the plant sections; a unit for detectingpaper roll products; wherein the unit for detecting paper roll productscomprises a camera system for capturing one or more images of arespective paper roll product; wherein the camera system comprises afirst camera which is positioned above the conveying section, the firstcamera including a first lens directed perpendicularly to the productsupporting surface and being configured to capture an image of anentirety of at least one chosen from a length and a width of therespective paper roll product; the electronic process controldetermining: the at least one chosen from the length and the width ofthe respective paper roll product based on the image captured by thefirst camera, and whether the at least one chosen from the length andthe width of the respective paper roll product is non-conforming.
 2. Theplant according to claim 1, wherein the unit for detecting paper rollproduct is situated at the conveying section between an upstream sectionof an operating line and a packaging section, and downstream of thepackaging section.
 3. The plant according to claim 1, wherein the firstcamera is positioned to capture an image of a top face of the respectivepaper roll product.
 4. The plant according to claim 1, wherein thecamera system is suitable for capturing an image of a front face of therespective paper roll product.
 5. The plant according to claim 1,wherein the camera system is suitable for capturing an image of a rearface of the respective paper roll product.
 6. The plant according toclaim 1, wherein the camera system further comprises a second camerapositioned above the conveying section and including a second lensinclined at a respective angle to the product supporting surface.
 7. Theplant according to claim 1, wherein the camera system further comprisesa further camera including a further lens inclined at a respective angleto the product supporting surface, the further lens being directed in adirection opposite to a feed direction of the product.
 8. The plantaccording to claim 1, wherein the camera system further comprises afurther camera including a further lens inclined at a respective angleto the product supporting surface, the further lens being directed in asame direction as a feed direction of the product.
 9. The plantaccording to claim 1, wherein the camera system has a depth of fieldsuch as to keep in focus a plurality of products of different sizes, inparticular different heights.
 10. The plant according to claim 1,wherein the unit for detecting paper roll products controls the camerasystem to capture the one or more images of the respective paper rollproduct as the respective paper roll product moves along the conveyingsection.
 11. The plant according to claim 1, wherein the unit fordetecting paper roll products comprises a light source for lighting theproducts at a respective detection zone.
 12. The plant according toclaim 1, wherein the electronic process control includes an industrialPC having corresponding programming or software.
 13. The plant accordingto claim 12, wherein the electronic process control is suitable forreceiving the image, processing the image and determining whether theproduct has one or more corresponding defects.
 14. The plant accordingto claim 13, wherein the electronic process control is suitable fordetermining a parameter representing a particular product characteristicto be assessed.
 15. The plant according to claim 14, wherein theelectronic process control is suitable for determining whether theproduct is defective or acceptable by determining whether a value of theparameter falls outside or inside a defined tolerance range around apredetermined reference value.
 16. The plant according to claim 15,wherein the tolerance range is selected or set at will by an operator incharge.
 17. The plant according to claim 12, and further comprising adisplay, wherein the electronic processing process control displays onthe display, a respective graphical interface or screen, which comprisesan information field which indicates whether the product is defective orconformant.